The objectives of this work are to obtain molecular information on the structure and function of a chloride channel, and to extend the work to the isolation of the gene for the transporter. The methods to be used are membrane isolation, reconstitution, transport specific fractionation, protein chemistry, and recombinant DNA techniques. The aim is to develop methods to study a chloride channel from animal tissues (bovine trachea and electric ray electroplax), and to use the cDNA for this protein to obtain information about the human protein(s).